Each record in the MIMIC II Clinical Database contains information about
a single patient. About 11% of the patients have been admitted to one or
more of our study ICUs more than once, and their records contain information
about all of these admissions, supplemented by limited additional information
collected during the intervals between ICU admissions. (In the MIMIC II
Waveform Database, however, each record contains information for only a
single ICU admission.)

Each record in the public subset is contained within a subdirectory of
this one. By visiting any of the numbered directories listed below,
it is possible to get a view of the record in chronological order, and
this may be useful to obtain an overview of the record. The same
information is contained in a WFDB annotation file within each
directory, and also in a plain text file, and either of these formats
will be more easily parsed by a computer program than the default
(HTML) view.

Many of the timestamps that appear in the MIMIC II Clinical Database were
manually entered into the ICU medical information systems as much as an hour
after the events to which they refer, and others were extracted from laboratory
reports that became available at varying times following the test. In such
cases, the MIMIC II Clinical Database includes both the time of data entry (the
time at which the information was first available in the medical record) and
the best available estimate of the time of the event or test itself. These
times are not perfectly synchronized with those in the corresponding MIMIC II
Waveform Database records, as a result of imperfect synchronization of clocks
as well as imprecise or faulty recall, and occasional transcription errors in
manual entry. As a result, one should not assume that the time order of events
separated by 15 minutes or less is known; for example, an intervention recorded
in the clinical database may appear a few minutes earlier than the event in the
waveform database that prompted the intervention.